Thulasi (aka Ocimum Sanctum) is having medicinal properties and many Hindu’s grow the plant at home. Also the Thulasi Malai (Garland of Thulasi) is a must for the Lord Perumal (Vishnu) in most temples this side of India.
Seen here is the Garland maker / seller in front of Sri Parthasarathi Swami Temple, Triplicane.